The present invention relates to a refrigerating or heat pumping process, as well as to an apparatus for performing this process. The process and apparatus use a paramagnetic substance and a fluid in contact therewith. It is applicable to refrigeration, particularly to very low temperatures, as well as to heat pumping.
It is known that refrigeration and heat pumping require similar installations. In heat pumping, the part of the installation is used, which gives off heat at high temperature to the ambient medium or to another body. In refrigeration, that part of the installation is used, which, at low temperature absorbs the heat of the ambient medium or of another body.
It is also known that refrigeration and heat pumping can be realized on the basis of a thermodynamic cycle, in which a certain quantity of heat is taken from a cold source, whilst another quantity of heat is restored to a hot source. The standard thermodynamic cycle in refrigeration or heat pumping is the Carnot cycle. This cycle generally comprises, in the case of a motor, the isothermal expansion of a gas, followed by an adiobatic expansion and then an isothermal compression and finally an adiobatic compression. During this cycle, the energy exchanges with the outside are in order: heat supply Q.sub.1, work production W.sub.1, heat removal Q.sub.2, work supply W.sub.2. The useful work W is given by the relation: EQU W=W.sub.1 -W.sub.2 =Q.sub.1 -Q.sub.2
which represents the area of the Carnot cycle. The efficiency can then be expressed by the relation: ##EQU1## In this relation, T.sub.2 is the temperature of the cold source, whilst T.sub.1 is the temperature of the hot source.
It is not possible to realize the Carnot cycle in refrigeration or heat pumping installations, due to heat exchange problems.